Wireless local area networks (WLANs) have evolved rapidly over the past few years. Progressive WLAN standards have focused primarily on improving data throughputs. For example, the peak data throughputs of IEEE standards 802.11b, 802.11a/g, 802.11n, and 802.11ac are respectively 11 Mbps, 54 Mbps, 600 Mbps, and 7 Gbps. IEEE 802.11ax targets a five to ten times average spectral efficiency gain at least in one dense deployment. It is desirable to increase the per-link data throughput by all means.
To increase data throughput, low-density parity-check (LDPC) codes are used to encode data in wireless networks. LDPC codes are linear block codes whose parity-check matrix H has a favorable property of being sparse, i.e., it contains only a low number of nonzero elements. Tanner graphs of such codes are bipartite graphs containing two different kinds of nodes: variable nodes and check nodes. An (n, k) LDPC code with a code rate k/n is represented by an m×n parity-check matrix H, where m=n-k denotes the redundancy (i.e., parity bits) of the coding scheme. The LDPC codes can be regular or irregular depending on degree distribution of variable nodes (column weights) and check nodes (row weights).